Apparatus for the smelting of copper ores and the like



March 15, 1932.

APPARATUS FOR THE SMELTING' OF COPPER ORES AND THE LIKE Original Filed Jan. 30, 1950 4 Sheets-Shet 1 A. e. MCGREGOR 1,850,025

A. G M GREGOR APPARATUS FOR THE SMELTING OF COPPER ORES AND THE LIKE v March 15, 1932.

Original Filed Jan. 30, 1930 4 Sheets-Sheet 2 v 172% Z27. m, MW

March 15, 1932.

A. G. M GREGoR APPARATUS FOR THE SMELTING OF COPPER ORES AND THE LIKE Original Filed Jan. 30, 1930 4 Sheefs-Sheet 3 March 15, 1932. C E R,

APPARATUS FOR THE SMELTING OF COPPER ORES AND THE LIKE Original Filed Jan. 30, 1930 4 Sheets-Sheet 4 the transfer between beratory furnaces,

machinery are requlred, and the skulls WlllCl'L inized, and the handling Patented Mar. 15, 1932 Tri Mia-n- ALEXANDER GRANT Moeaneon, or Lennon, E GLAND- APPARATUS FOR THE SMELTING OF COPPER ORES AND THE LIKE original application filcdi'anuary '30, 1930, Serial Divided and this application filed July 25, 1930.

concurrent application Serial No. 336,28,

filed 30th January,

1930, from which application the present invention is divided. T ie present invention is hereinafter specifically described with reference to the smelting o,

, copper sulphide ores,

It is an object of this invention to provide simplified apparatus in which heat is conserved, the fuel required for smelting is very materially reduced, dusting losses are miniof the products in a heated condition is avoided, and the use of such apparatus will result in increased recoveries as well as less expensive plant, maintenance and labour costs.

The usual procedure of copper smelting consists broadly in roasting or calcining the ore in roaster furnaces, thereafter produc ing matte in reverberatory or like furnaces, and then 111 a separate operation bessemerizing the matte to blister copper in converters.

These-operations require specialplant for handling the ore between the various operations, and as the 'ore after roasting is hot, dry and dusty, much heat and dust are lostin the roasters andthe reverberatory furnaces. In the transfer of the matte .fom the reverberatory furnaces to the and in the transfer of the coin converters, verter slag from the converters to the reverheat is lost, labour and form in the transfer lauders and ladlesmust be gathered and broken up and re-smelted- According to the present invention, the

smelting is carried out in a reverberatory furnacechamber having a length considerably in excess of its breadth or height and mounted to tilt about a her being provided with an axial furnace outet for gases connected to air-preheat ng ap-- paratus or waste heat boilers through an axial land, whereby tilting of the furnace is permitted without diluting the-outgoing gases Tuyeres are prowith the atmospheric air.

the bottom thereof vided in the furnace near No. 336,288, and in Belgian Congo, December further modified longitudinal axis, the cham- Serial No. 470,707.

supplied from a longitudinally-extending air blast pipe and fuel burners areprovided in the end opposite from the outlet for gases.

The furnace-gases, after cooling, may be treated for the recovery. of sulphur dioxide, and owing to the fact that they are not diluted with excess of atmospheric air suchrecovery is simplified.

- Further features of the invention Will appear from the following description of certain specific forms of the apparatus, which are glven byway of example only, and with reference to the accompanying drawings, in whichv Figure 1 is mainly a longitudinal sectional elevation of one form accordance with the invention;

Figure 2 is a plan partly in section of the same; i

Figures 3, through the furnace, various positions;

I Figures 6 and 7 apparatus. (V V Figure 8- shows a waste heat boiler; Figure 9 is a longitudinal section, and

amend 5 are cross-sections showing it tilted to Figure 1 0,is a plan partly in section of a modified construction; 7

Figure 11 is a cross-section oft-he same, and Figure, 12- is a longitiudinal section of a construction. Like reference numerals indicate throughout the severalviews.

Referring to the construction illustrated in Figures 1 to 8, a reverberatory furnace chamber 20 is-provided, the length of which is considerably greater than its breadth or height, and which is of the cross-section illustrated in Figures 3, 4 and 5. This is mounted on the framework 21 having curved bearers 22 beneath the furnace which rest on rollers 23 supported by curved base-plates '24. This provides a tilting mounting for the furnace.

Gearing 25, which meshes with curved racks 26, isprovided for effecting the tilting movements. The furnace is built upv of highly refractory material. Along one side of the'furnace extends an air blast or bustle pipe 30, having branches 31 to tpyeres 32 located in the side like parts of the apparatus n are details of ore-charging of the furnace near the bottom thereof. Above and below the tuyeres 32 there may be located in the wall of the furnace watercooling plates 33 with the necessary waterconnections (not shown) where water-cooling is desirable. On the opposite side of the furnace from the tuyeres are a number of charging doors 34, and near one end there is a slag-discharge-spout 35. On the charging side of the furn'aceis a framework 40 supporting a track 41 for charging-cars 42. The cars carry ore-hoppers 43 and charging devices to deliver ore through the doors 34 into the furnace. The charging devices are hereinafter more fully described. Below the platform 40 is a second track 44 on which run slag-cars 45 to receive slag discharged from the spout 35. At the back of the furnace is a third track 46 on which run cars 47 supporting pots 48 to receive molten copper. The molten copper is tapped from the furnace through a discharge-opening, which 'is not shown in the drawings. I

Referring to Figures 4 to 7, the charging devices for the furnace comprise a belt 50 supported on rollers'51 which are carried on a charging frame 52. The frame 52 is mounted on wheels 53 (Figures 4 and 5) so that it can be advanced towards, and retracted from, the furnace. The wheels 53 run on a carrier 54, which is pivoted on the car 42. The belt 50 is driven at a high speed by an electricmotor mounted on'the frame 52 but not shown in the drawings. The hopper 43 has a discharge regulating device 55 for delivering ore'on to the belt 50. Below the belt 50 a sliding bracket is mounted-on-the frame 52 and-carries a pan 61, which can'be advanced, when desired, into the charging door of the furnace.

I The pan 61 has a spout 62 on its front side anda nozzle 63 supplied by an air-pipe 64 upon the back. The nozzle '63 serves to direct a jet of air under pressure into the pan and out through'the spout 62..

The operationof the charging device is as follows l Ore delivered'on to thebelt 50 from the hopper 43 is projected therefrom, either directly into the furn.ace,'or, if desired, into the pan 61.

If the ore is projected directly into the furnace, the belt 50 may be run at a sufficient speed to spread the ore across the whole width of the furnace. If the ore or other material of the charge is delivered into the pan 61 the pressure jet from the nozzle 63 serves to deliver it into the furnace through the spout 62. The pan '61 is pivotally mounted at 64 and can be swung through an angle indicated by the chain-lines in Figure 7 so as to distribute. the material uniformly over a large area of the surface of the charge within the furnace. V,

Reverting to Figures 1 and 2, the furnacechamber 20 is provided with an axial outlet 7 0 connected through a coaxial gland 71 with a flue 72. The flue 72 branches into two lateral flues 7 3, 74, provided with water-cooled dampers 75, 76. In these flues are located waste-heat boilers 7 7 cooling the molten particles held in suspension by the furnace gases, this cooling being sufficient only to prevent accretions and crusts adhering to the sidesof the subsequent fines and brickwork, and the gases,

after passing through the waste-heat boilers,

are led through suitable reversing valves to regenerators80, 81. The air blast or bustlepipe 30, which tilts with the furnace, is led over the end of the flue 72 to a. coaxial gland 82 by which it is connected to a branched pipe 83, which is connected to the regenerators 80, 81. The connections to the regenerators are as follows :The flues 73, 74 from the furnace are connected to a cross-flue 90, and the crossflue 90 is connected by two water-cooled valves 91, 92 to the regenerator 81. It is connected through two other water-cooled valves 93, 94 to the regenerator 80. By operating these valves the cross-flue 90 maybe connected to either of the regenerators as desired. The branched pipe 83 is connected by a valve 94' to the regenerator '80, and by a valve 95 to the regenerator8l. 5

Thus, it will be seen that hot gases coming from the furnace-chamber 20 pass by wayof the flues 73, 74 through the Waste-heat boilers 77, 78 to the cross-header 90, and thence to one of the 'regenerator-chambers 80. Mean- While, air can be drawn in through the other regenerator by way of the branched pipe 83,

1, (8 for the purpose of to the bustle-pipe 30. The connections are reversed by operating the valves 91 to 95, and when this isdone, the flow of gases through the waste-heat boilers 77, 78 can be maintained in the same proportions as before by suitably adjusting the dampers 75, 76.

Openings 100 are provided in the other end I provided with any outer brick-lined casing l 111 and hot gases from the chequered brickwork chamber pass through the space provided between the chequered brickwork chamher and the brick-lined casing 111 to an outletflue 112. The outlet-flue 112 may be either a forced draught outlet having an injectornozzle 113, if ings, or it may be connected to a stack for natural draught. A damper 114 controls the outlet and there is an air-inlet 115. When desired, as shown in the draw- 7 the regenerator is in use for heating air for the bustle-pipe 30, the damper'll t is closed, air is blown in through the lined casing 111, and thence through the chequered brickwork chamber to the valves and bustle-pipe already described.

- The operation of the process in the above apparatus is as follows :-It is assumed that the sulphur content of the entire charge to be smelted will be 20 per cent. or more. The furnace is of large size and may be fifty to sixty feet long, or even larger. I

Taking as starting point the beginning of a fresh cycle of operations after most of a previously smelted charge of molten copper has been removed from the furnace, the operations will be so arranged that part of the slag and copper from the immediately preceding operation of blowing to blister copper will remain. This initial charge of hot molten slag and copper sufiices to ignite the fresh charge.

Firstly, a new charge is introduced which is high in sulphur and iron with the object of producing a low-grade matte quickly. Air is blown into the charge with the result that sulphur is oxidized and a molten matte is produced. If additional heat is necessary it can be supplied by the fuel burners 100. For the blowing operation, the furnace wouldbe tilted back into the position'shown in Figure 4 so that the tuyeres are covered .by the charge. As will be understood, care is taken in charging the of such constituents that a proper slag 1s formed. Additional ore and other materials for the charge are added from time to time and the blowing continued until the furnace is filled with a low-grade matte and slag. In the present process as soon as the furnace is filled to its capacity with molten slag and matte the furnace is tilted to bring the tuyere above the bath, the air-blast is turned ed and a thin layer of preferably pyritic copper ore or other fluxes is spread evenly over the surface of the slag, by means of the pan 61 and directing nozzle 62. The fuel burners are now turned on and the pyrite ore is melted down. The pyrite charge when melted produces a low-grade matte which intermingles with the slag as it passes downwards and by its strong affinity for the copper present in the slag carries the copper with it into the matte below, previously produced. Ihe effect is that the slag is cleaned of copper. This cleaning of the slag in the same furnace chamber after bessemerizing is an important feature of the process to which the invention is adapted as in the usual bessemerizing converter practice it is necessary to transfer the slag to another furnace for cleaning with another charge.

When the slag is cleaned sufficiently, the burners may be turned off and the furnace pipe 115, passes through the outer space within. the brickfurnace to provide a charge is tilted over to a position in which the slagspout 35 will suffice to discharge the molten slag from above the matte. skimmed rapidly into slag-cars 15 and the furnace is then tilted back again. A further amount of ore is charged into the furnace,

preferably containing a larger proportion of silica than during the first blow to allow for a greater oxidation of iron and a matte higher in copper atthe end of the second blow. The furnace is then given asecond blowing, and this and charging is continued until the furnace is again filled and ready to be skimmed a second time. The slag is thereafter cleaned and discharged as before, and

the operationrepeated until the furnace contains a full harge of matte of a higher copper content,which may finally bebrought up to or, SOper cent; After the slag has been skimmed from this matte, or white metal as it is called, the charge is further blown by air to bring it to the condition of blister cop-' per. The copper is tapped nearthe bottom of the furnace from under the slag, and the slag and asufficient amount, if necessary, 0 molten copper, is left in thefurnace to com mence a fresh cycle of operations.

Referring to the modified apparatus shown in Figures 9 to 11, this-comprises a tilting furnace-cha1nber'12O mounted on rollers 121 and provided. with an axial-outlet for furnace-gases'122 connected by a gland 123 to a flue 1241, and the flue 124 leadseventually through suitable valves 125 to a pair of regenerators126, 127. The regenerators are also connectedby a cross-header 128 to an air-blast or bustle-pipe 129, by way of a coaxial-gland 130. Theobustle-pipe is provided with branch pipes 131 leading to, tuyeres 132, and with a connection. 133 to liquid-: or powdered-fuel burners 134. The constructionso far described is similar to that illustrated in Figures 1 and 2, but it is to be observed that the'fiue 12 1 is not branched and does not contain any. waste-heat boilers. On the otherhand, it is made of a U-shape in vertical section, as shown in Figure 9, so that slag, matte and other materials carried over in the furnace-gases may be thrown down before entering the regenerators 126. V

In the construction illustrated in Figures; 1 and 2, the suspended matters carried over in the furnace-gases are intended to be thrown down in the fines 73, 7e and the waste-heat boilers 77, 78. The latter, as will be appreciated, are more easily cleaned of deposited material than are the regenerators and, moreover, as their surfacesare relatively cool they tend to throw down the suspended matters in the form of dust rather than to" allow them to accumulate in molten or coagulated masses- The slag is In operating accordingto the present inore is charged into the furnace 1n its natural appreciated, in this case the waste state, which is cold and moist, and is not liable to give rise tothe production of dust in anything like the same degree as is the ordinary dry and dusty calcined product of a roasting operation as ordinarily charged into a reverberatory furnace.

' Referring to Figure 12, this shows a furnace-chamber 220 provided with tuyeres 232 and liquid-fuel burners 234, the furnace being provided with an axial outlet 222 connected through a gland 228. to .wasteheat boilers 224. The outgoing gases, however, instead of passing through regenerators for treating the blast are passed into waste heat boilers only. A connection 246, 247 is provided to a chimney-stack, which is not illustrated in the drawings and an alternative flue 240 to an acid recovery plant 245 is indicated diagrammatically in the drawings. The furnace is mounted'on rollers, as before. As will be heat boilers would be design-ed to absorb as large aproportion as feasible of the heat carried by the outgoing gases. The outgoing gases, being rich in S0 can be employed for the recovery of this constitutent where there is a market for it. i V Y It-will be'unders'tood that while the description hereinbefore relates specially to copper and the minerals of copper, the apparatus will be equally adapted to the smelting of nickel sulphides, which occur with copper sulphide ores, to matte, and to the smelting of other sulphide ores.

The tilting furnace arranged with tuyeres on the side, as described, could be used for converting matte only,-in place of the ordinary converter. The end discharge and the axial gland for the outgoing gases prevents dilution with the outside air and the heat in the gases or the S0 content could be more readily utilized for steam or acid respectively than in the ordinary converter.

I claim 1. In combination, a furnace, for the smelting of copper-ores and the like, comprising a reverberatory furnace-chamber having a length considerably in excess of its breadth or heig t and mounted to'tilt about a longi tudinal axis, air-preheating apparatus therefor, an axial furnace-outlet for gases connected to the air-preheating apparatus, an axial gland in said outlet to permit tilting of the furnace, tuyeres in the furnace near the bottom thereof, and an air-blast pipe extend ing along the furnace with branches to the tu'yeres, the air-blast pipe'being connected to the air-preheating apparatus.

2. A furnace as claimed in claim 1 provided with a plurality of charging doors along the oppositeside thereof from the air-tuyres.

3. The combination with a furnace as claimed in claim 1 of means for introducing an ore-charge,said means comprising an orchopper, a charging belt mounted beneath the hopper, and means to drive it at a speed sufficient to throw the ore into the furnace.

4. The combination with .a furnace as claimed in claim 1 of means for introducing an ore-charge, said means comprising an orehopper, a charging belt mounted beneath the hopper, means to drive it at a speed sufficient to throw the ore into the furnace, and directing means to spread the driven ore over a wide area within the furnace.

A furnace as claimed in claim 1, wherein the hot blast pipe is connected also to fuel burners at one end.

, In testimony whereof I aflix my signature. ALEXANDER GRANT MGGREGOR. 

